The present invention relates to centrifuge devices, and more particularly to an automated laboratory centrifuge which is used in combination with a combination specimen container and microscope slide. One such combination specimen container and microscope slide is described in U.S. Pat. No. 5,030,421, and is currently commercially available under the name Censlide.TM.. Such combination specimen containers and microscope slides are referred to as Censlide containers.
The use of centrifuges in laboratories to separate solids from biological fluids is widespread. In small clinics and physician offices, procedures such as performing urinalysis are time consuming, unstandardized and costly. The centrifuge of the present invention, with its Censlide container reduces procedural time, increases standardization of testing and reduces cost to enable small labs to become more profitable and possibly reducing costs for the patient.
Using the standard urinalysis method, urine is poured into a centrifuge tube, which is typically an ordinary test tube. The centrifuge tube is centrifuged for five minutes and the supernatant (liquid portion above the sediment) is poured off leaving a small volume of urine on top of the pellet (sediment). A pipette is introduced into the centrifuge tube and the pellet is re-suspended by aspirating and dispelling the sediment suspension. A small volume is aspirated into a pipet and one drop of the suspension is placed on a microscope slide. A coverslip is then placed over the drop and the slide is microscopically examined. The elements within the urine are determined by morphological features and thus the urinalysis is performed.
An improvement of this basic procedure is described in U.S. Pat. No. 5,030,421, to Louis F. Muller, entitled "Integral Centrifuge Tube and Specimen Slide." In the Muller patent, the Censlide container (tube) is described as having an upper, hollow, generally tubular portion which serves as a specimen collection member. The same tube also has a central specimen collection space in communication with the upper end of the container. This device also includes a lower integral microscope slide member having transparent flat front and rear walls throughout a part of its length, and which is in communication with the upper specimen collection space.
The transition for the specimen collection space to the microscope slide member is smooth, and the entire unit operates as an integral centrifuge tube and specimen slide. An internally fitting cap or closure is provided at the upper end of the container. Thus, once the sample is taken, it may be centrifuged and examined without having to re-open the container, or otherwise transfer the materials within the container.
Although the Censlide container has structures designed to facilitate the formation of a desired evenly spread array of centrifuged elements across its microscope slide member, packing may nonetheless occur if the centrifugation occurs for too long a time, or if the centrifugal force is sufficient to deform the microscope slide member of the container. In the event of packing it is desirable to tap or flick the Censlide container to disperse the packed material. This dispersion by a flicking action produces a more even distribution of the sediment across the microscope slide member portion of the tube.
Finger flicking of the Censlide container often does not allow enough energy input into the microscope slide member of the Censlide container to dislodge packed material. In addition, the technique of manual flicking varies from individual to individual, causing the lack of standardization of the dispersal of the packed material. Manual flicking of the Censlide container may also create scratches or deform the microscope slide member portion viewing area, which can interfere in microscopic examination.
Most existing and currently available centrifuges must be timed during centrifugation and calibrated to the appropriate relative centrifugal force to ensure that adequate separation occurs without excessive packing. It is currently necessary for a lab technician to manually time these centrifuges with a timer, therefore increasing labor costs and increasing the chance of human error, and adding more variables to standardizing the technique.
The present invention addresses the above problems by automating and thereby standardizing the urinalysis procedure.